1. Field of Invention
The present invention relates to rodent control devices; specifically an audio signal to be used on rodent traps of a type wherein a rodent attempting to feed on a bait triggers a coiled spring loaded trapping jaw.
2. Description of Prior Art
Rodent traps with a spring actuated trapping jaw have long been a simple and effective means of rodent abatement. In practice these traps are set, placed, and then checked on a periodic basis, usually daily, to assure that a trapped rodent does not escape, a deceased rodent is not fed upon, a deceased rodent does not create odors, and finally to free up the trap and reset it allowing other rodents to then be trapped. As rodents tend to hide in small dark places within attics, corners and outbuildings: traps placed in these areas are difficult to access during periodic trap checks. If it were known when a trap had been triggered; periodic trap checks would not be required. Therefore it has long been desirable to provide a signal that activates when a trap has been triggered.
In U.S. Pat. No. 1,290,697 of 1919 the animal trap of Banash contains a bell signaling means. A one time signal such as this requires the trapper to be nearby, while the animal to be trapped must not be scared off by a tinkling bell while investigating the trap.
Later in Barber's U.S. Pat. No. 2,554,728 in 1951, an electrical switch is attached to each animal trap so that animal trappers have the capability of remotely checking trap condition.
Agron's U.S. Pat. No.4,517,557 in 1985 is directed toward spring loaded rodent traps and employs a frame with integral switch in which a rodent trap is inserted. An unspecified remote indicator means then senses a change in state of the switch when the inserted rodent trap separates from the surrounding frame. This sensing arrangement has numerous limitations and drawbacks: (1) The inserted trap must fit precisely with the sense-frame to allow the switch to operate correctly. (2) Due to the numerous variables and interrelations between trap, frame and rodent; the inserted trap does not necessarily jump out of the frame device upon the trap being triggered. (3) The use of an external signaling means requires one or more traps to be wired to the signaling device; which is time-consuming, unsightly, a tripping hazard and an added expense.
In Disalvo's U.S. Pat. No. 5,154,017 of Oct. 13, 1992 the rodent trap itself is used as a base to fasten and connect the various parts for this signaling mechanism and the metal wire jaw member is made part of the circuit. A DC buzzer is connected to a 9 Volt battery that is in series with a switch formed by the jaw member itself and a conductive spring mounted on the trigger side of the trap. Several drawbacks to this device limit its commercial application: (1) The parts comprising the signaling means in the preferred embodiment are far too large to be employed with small traps, such as mouse traps: note the size of a 9 Volt battery. (2) The switch mechanism used requires conduction through disparate trap member sections whose electrical contact is problematic; considering the conditions under which the trap is required to operate. (3) The spring-loaded jaw member, or killing member, of the trap is required to make contact with a spring on the side of the trap whereby the rodent is to be trapped; if any portion of the rodent gets pinched between the jaw member and spring contact, or if the rodent is trapped with a large portion of its body near the center of the trap, the jaw member will not properly contact the spring contact. (4) The spring contact is located near the pivot point of the cross member around which the jaw member rotates such that when the jaw member is triggered the spring contact mechanism forms a fulcrum. Upon triggering; the jaw member sharply strikes the spring mechanism thus imposing a vertical load on the wire staple or means of holding the cross member, or pivoting section of the jaw, to the base. The vertical force is greatly pronounced upon triggering when no rodent is trapped, and leads to premature trap failure. (5) Separate elements of spring contact, buzzer and battery are mounted permanently to the trap with members affixed to both the trapping means and the base assembly. This is a lengthy and costly assembly process. (6) Wiring connected between elements of the trap, especially those going out to the spring assembly, must be made resistant to a rodent's gnawing, tugging, or other destruction. The embodiment speaks of routing the wiring through grooves that are then covered. (7) The signaling mechanism can not easily be removed and reattached to another rodent trap when the one on which it resides becomes soiled or is otherwise no longer useable. (8) How is this trap to be stored? No mechanism is specified for preventing the signal from operating while the trap is being stored. As traps are stored in an uncocked position for reasons of safety, either the battery of this trap must be removed or a separate insulating means must be inserted between the spring contact and jaw member. In either of these cases the jaw member under the force of the drive springs, will still fully compress the spring contact against the base thereby in a short period of time reduce its operating free height and ability as a jaw member contact. (9) Once activated the audio signal buzzes constantly for a period of minutes or hours until the battery depletes. Continuous buzzing can constitute an obnoxious annoyance to nearby individuals whose only recourse is to immediately find and disable the trap signal. Additionally, if no one is near the trap for a period of hours after it is triggered, the condition of the trap will be unknown: the battery will have been depleted in that time period. Overall the use of an electrical DC buzzer, the large battery, the non-trivial assembly requirements, and the problems associated with the use of the spring contact make this trap signal overly large, costly and unreliable.
Brewer's U.S. Pat. No. 5,184,416 of Feb. 9, 1993 employs an external signaling device wired to a pair of contacts positioned to contact the jaw member and conduct through that jaw member between the contacts to form a switch. These connections with the jaw member take place on the outermost section of the jaw, the same section of the jaw intended to strike the rodent. Large drawbacks exist both in using an external signal source and in getting the rodent to cooperate so as to be trapped in a manner that allows both contacts to maintain continuity with the jaw member.
Orsano's Signaling Apparatus for Use with a Disposable Animal Trap, U.S. Pat. No. 5,477,635 of Dec. 26, 1995 employs a trap housing means containing the sense and signaling device. This patent employs a light and light receptor or an unspecified "equivalent mechanical means", that together sense movement of the jaw member as it passes through the area above where it is being retained by the jaw retaining member. Numerous disadvantages exist with commercializing this signaling apparatus: (1) A housing of dimensions substantially larger than the disposable trap to be used is required. (2) The disposable rodent trap must be retained in a fixed position relative to the sense mechanism within the signaling base. The attachment means of the preferred embodiment would not properly retain rodent traps whose dimensions varied from the one for which the signaling base apparatus was designed. Furthermore the sense mechanism relies on a physical relation between disposable trap and signaling base. Therefore a single unit design will not accommodate variously sized traps such as mouse and rat traps, and may not work properly with traps of differing manufacture. (3) The required sense mechanism must be made very sensitive as it must sense the thin wire jaw member as it moves rapidly through the sense region. (4) The audio signal is not in this case generated as based upon a steady state event as in previous designs, wherein a switch changed state and remained in that state. The signaling unit of this device records and latches an event when the sense mechanism detects an object in its field. This latched event is then what the output of the audio signal is based upon. (5) With reference to disadvantages 3 and 4 above; the sense mechanism may indeed sense the movement of the jaw member as described, yet it may identically sense a rodent crawling over that same area, or a fly, insect or other object that impinges or otherwise exists for more than few milliseconds above the retained jaw member. (6) Rodents may be wary of approaching a light beam as shown in the preferred embodiment. (7) A light source and sense mechanism draws power from its electrical power source at all times. The power source could be depleted without the trap even getting triggered, therefore periodic inspection would be needed to assure that the power source had not yet been depleted. (8) Finally the mechanism is large, complicated, and expensive to manufacture.
Possibly due in part to the inherent drawbacks, the above embodiments are not known commercially at the time of this application. Furthermore, at the time of this application no rodent trap signaling products are known to exist commercially that provide a suitably inexpensive means for signaling that a rodent trap, such as a mouse trap or rat trap, have been triggered.